name stringlengths 5 6 | title stringlengths 8 144 | abstract stringlengths 0 2.68k | fulltext stringlengths 1.78k 95k | keywords stringlengths 22 532 |
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510987 | Bounded Model Checking Using Satisfiability Solving. | The phrase model checking refers to algorithms for exploring the state space of a transition system to determine if it obeys a specification of its intended behavior. These algorithms can perform exhaustive verification in a highly automatic manner, and, thus, have attracted much interest in industry. Model checking pr... | Figure
must cause the initial state to be visited infinitely often. While there is no particular reason a counter
should work this way, we use the example to illustrate how fairness constraints are imposed in bounded model
checking. Given such a fairness constraint, a counterexample to the liveness property AF(b^a) wo... | model checking;cone of influence reduction;processor verification;bounded model checking;satisfiability |
511261 | Complexity Analysis of Successive Convex Relaxation Methods for Nonconvex Sets. | This paper discusses computational complexity of conceptual successive convex relaxation methods proposed by Kojima and Tunel for approximating a convex relaxation of a compact subsetof the n-dimensional Euclidean spaceR n . Here,C0 denotes a nonempty compact convex subset ofR n , anda set of finitely or infinitely man... | Introduction
.
In their paper [2], Kojima and Tun-cel proposed a class of successive convex relaxation
methods for a general nonconvex quadratic program:
maximize c T x subject to x 2 F; (1)
where
a constant column vector in the n-dimensional Euclidean space R n ;
(we often write F instead of F (C
compact convex subset... | global optimization;convex relaxation;complexity;nonconvex quadratic program;semidefinite programming;sdp relaxation;lift-and-project procedure |
511444 | Cross-entropy and rare events for maximal cut and partition problems. | We show how to solve the maximal cut and partition problems using a randomized algorithm based on the cross-entropy method. For the maximal cut problem, the proposed algorithm employs an auxiliary Bernoulli distribution, which transforms the original deterministic network into an associated stochastic one, called the a... | Introduction
Most combinatorial optimization problems are NP-hard; for example, deterministic and
stochastic (noisy) scheduling, the traveling salesman problem (TSP), the maximal cut in
a network, the longest path in a network, optimal buer allocation in a production line,
optimal routing in deterministic and stochasti... | cross-entropy;importance sampling;rare event simulation;combinatorial optimization |
511466 | Accelerated focused crawling through online relevance feedback. | The organization of HTML into a tag tree structure, which is rendered by browsers as roughly rectangular regions with embedded text and HREF links, greatly helps surfers locate and click on links that best satisfy their information need. Can an automatic program emulate this human behavior and thereby learn to predict ... | (Note: The HTML version of this paper is best viewed using
Microsoft Internet Explorer. To view the HTML version using
Netscape, add the following line to your ~/.Xdefaults or
~/.Xresources le:
Netscape*documentFonts.charset*adobe-fontspecific: iso-8859-1
For printing use the PDF version, as browsers may not print the
... | reinforcement learning;document object model;focused crawling |
511488 | Extracting query modifications from nonlinear SVMs. | When searching the WWW, users often desire results restricted to a particular document category. Ideally, a user would be able to filter results with a text classifier to minimize false positive results; however, current search engines allow only simple query modifications. To automate the process of generating effecti... | INTRODUCTION
When searching the WWW, users often desire results from a
specific category, such as personal home pages or conference an-
nouncements. Unfortunately, many search engines return results
from multiple categories, thus forcing the user to manually filter
the results. One solution is to use an automated class... | query modification;sensitivity analysis;support vector machine;rule extraction |
511496 | Choosing reputable servents in a P2P network. | Peer-to-peer information sharing environments are increasingly gaining acceptance on the Internet as they provide an infrastructure in which the desired information can be located and downloaded while preserving the anonymity of both requestors and providers. As recent experience with P2P environments such as Gnutella ... | INTRODUCTION
In the world of Internet technologies, peer-to-peer (P2P)
solutions are currently receiving considerable interest [6].
communication software is increasingly being used to
allow individual hosts to anonymously share and distribute
various types of information over the Internet [15]. While
systems based on ... | reputation;credibility;P2P network;polling protocol |
511502 | Evaluating strategies for similarity search on the web. | Finding pages on the Web that are similar to a query page (Related Pages) is an important component of modern search engines. A variety of strategies have been proposed for answering Related Pages queries, but comparative evaluation by user studies is expensive, especially when large strategy spaces must be searched (e... | INTRODUCTION
The goal of Web-page similarity search is to allow users
to nd Web pages similar to a query page [12]. In partic-
ular, given a query document, a similarity-search algorithm
This work was supported by the National Science Foundation
under Grant IIS-0085896.
y Supported by an NSF Graduate Research Fellowshi... | evaluation;open directory project;related pages;search;similarity search |
511509 | An event-condition-action language for XML. | XML repositories are now a widespread means for storing and exchanging information on the Web. As these repositories become increasingly used in dynamic applications such as e-commerce, there is a rapidly growing need for a mechanism to incorporate reactive functionality in an XML setting. Event-condition-action (ECA) ... | Introduction
XML is becoming a dominant standard for storing and exchanging information. With its increasing
use in areas such as data warehousing and e-commerce [13, 14, 18, 22, 28], there is a rapidly growing
need for rule-based technology to support reactive functionality on XML repositories. Event-condition-
action... | reactive functionality;XML repositories;event-condition-action rules;XML;rule analysis |
511520 | Using web structure for classifying and describing web pages. | The structure of the web is increasingly being used to improve organization, search, and analysis of information on the web. For example, Google uses the text in citing documents (documents that link to the target document) for search. We analyze the relative utility of document text, and the text in citing documents n... | Introduction
The Web is a large collection of heterogeneous documents. Recent estimates predict the size of the indexable
web to be more than 4 billion pages. Web pages, unlike standard text collections, can contain both multimedia
(images, sounds, flash, etc.) and connections to other documents (through hyperlinks). H... | evaluation;anchortext;classification;SVM;entropy based feature extraction;web directory;web structure;cluster naming |
511526 | Translating XSLT programs to Efficient SQL queries. | We present an algorithm for translating XSLT programs into SQL. Our context is that of virtual XML publishing, in which a single XML view is defined from a relational database, and subsequently queried with XSLT programs. Each XSLT program is translated into a single SQL query and run entirely in the database engine. O... | INTRODUCTION
XSLT is an increasingly popular language for processing XML
data. Based on a recursive paradigm, it is relatively easy to use
for programmers accustomed to a functional recursive style of pro-
gramming. While originally designed to serve as a stylesheet, to
map XML into HTML, it is increasingly used in oth... | SQL;XSLT;query optimization;translation;XML;virtual view |
512165 | Fuzzy topological predicates, their properties, and their integration into query languages. | For a long time topological relationships between spatial objects have been a main focus of research on spatial data handling and reasoning. They have especially been integrated into query languages of spatial database systems and geographical information systems. One of their fundamental features is that they operate ... | INTRODUCTION
Representing, storing, quering, and manipulating spatial information
is important for many non-standard database applications.
Specialized systems like geographical information systems (GIS),
spatial database systems, and image database systems to some extent
provide the needed technology to support these ... | fuzzy region;fuzzy spatial query language |
512181 | Improving min/max aggregation over spatial objects. | We examine the problem of computing MIN/MAX aggregates over a collection of spatial objects. Each spatial object is associated with a weight (value), for example, the average temperature or rainfall over the area covered by the object. Given a query rectangle, the MIN/MAX problem computes the minimum/maximum weight amo... | Introduction
Computing aggregates over objects with non-zero extents has received a lot of attention recently
([YW01, ZMT+01, PKZ+01, ZTG+01]). Formally, the general box-aggregation problem is dened
as: \given n weighted rectangular objects and a query rectangle r in the d-dimensional space, nd
the aggregate weight ove... | min/max;indexing;spatial aggregates |
512447 | Dynamic memory management for programmable devices. | The paper presents the design and implementation of a novel dynamic memory-management scheme for ESP---a language for programmable devices. The firmware for programmable devices has to be fast and reliable. To support high performance, ESP provides an explicit memory-management interface that can be implemented efficie... | INTRODUCTION
Traditionally, devices implement simple functionality that
is usually implemented in hardware. All the complex functionality
is implemented in device drivers running on the
main processor. However, as devices get faster, it is increasingly
harder for software running on the main CPU to keep
up with the dev... | programmable devices;reference counting;dynamic memory management;model checking |
512449 | Accurate garbage collection in an uncooperative environment. | Previous attempts at garbage collection in uncooperative environments have generally used conservative or mostly-conservative approaches. We describe a technique for doing fully type-accurate garbage collection in an uncooperative environment, using a "shadow stack" to link structs of pointer-containing variables, toge... | INTRODUCTION
New programming language implementations usually
need to support a variety of di#erent hardware architectures,
because programmers demand portability. And because programmers
also demand e#ciency, new programming language
implementations often need to eventually generate
native code, whether at compile tim... | multithreading;garbage collection;programming language implementation |
512510 | Ordered binary decision diagrams as knowledge-bases. | We consider the use of ordered binary decision diagrams (OBDDs) as a means of realizing knowledge-bases, and show that, from the view point of space requirement, the OBDD-based representation is more efficient and suitable in some cases, compared with the traditional CNF-based and/or model-based representations. We the... | Introduction
Logical formulae are one of the traditional means of representing knowledge in AI [11]. However,
it is known that deduction from a set of propositional clauses is co-NP-complete and abduction
is NP-complete [13]. Recently, an alternative way of representing knowledge, i.e., by a subset
of its models, which... | unate functions;recognition problems;ordered binary decision diagrams OBDDs;automated reasoning;horn functions;knowledge representation |
512523 | Objects and classes in Algol-like languages. | Many object-oriented languages used in practice descend from Algol. With this motivation, we study the theoretical issues underlying such languages via the theory of Algol-like languages. It is shown that the basic framework of this theory extends cleanly and elegantly to the concepts of objects and classes. Moreover, ... | Introduction
Object-oriented programming first developed in the context
of Algol-like languages in the form of Simula 67 [17]. The
majority of object-oriented languages used in practice claim
either direct or indirect descent from Algol. Thus, it seems
entirely appropriate to study the concepts of object-oriented
progr... | relational parametricity;semantics;algol-like languages;object-oriented programming;specification logic |
512531 | Flow-sensitive type qualifiers. | We present a system for extending standard type systems with flow-sensitive type qualifiers. Users annotate their programs with type qualifiers, and inference checks that the annotations are correct. In our system only the type qualifiers are modeled flow-sensitively---the underlying standard types are unchanged, which... | INTRODUCTION
Standard type systems are flow-insensitive, meaning a
value's type is the same everywhere. However, many important
program properties are flow-sensitive. Checking such
properties requires associating di#erent facts with a value at
di#erent program points.
This paper shows how to extend standard type system... | constraints;effect inference;linux kernel;restrict;locking;flow-sensitivity;type qualifiers;types;alias analysis |
512542 | Profile-guided code compression. | As computers are increasingly used in contexts where the amount of available memory is limited, it becomes important to devise techniques that reduce the memory footprint of application programs while leaving them in an executable form. This paper describes an approach to applying data compression techniques to reduce ... | INTRODUCTION
In recent years there has been an increasing trend towards the
incorporation of computers into a wide variety of devices, such as
palm-tops, telephones, embedded controllers, etc. In many of these
devices, the amount of memory available is limited, due to considerations
such as space, weight, power consump... | dynamic decompression;code compression;code size reduction;code compaction |
512550 | A compiler approach to fast hardware design space exploration in FPGA-based systems. | The current practice of mapping computations to custom hardware implementations requires programmers to assume the role of hardware designers. In tuning the performance of their hardware implementation, designers manually apply loop transformations such as loop unrolling. designers manually apply loop transformations. ... | INTRODUCTION
The extreme flexibility of Field Programmable Gate Arrays
has made them the medium of choice for fast
hardware prototyping and a popular vehicle for the realization
of custom computing machines. FPGAs are composed
of thousands of small programmable logic cells dynamically
interconnected to allow the implem... | design space exploration;loop transformations;reuse analysis;data dependence analysis |
513071 | Stack and Queue Integrity on Hostile Platforms. | When computationally intensive tasks have to be carried out on trusted, but limited, platforms such as smart cards, it becomes necessary to compensate for the limited resources (memory, CPU speed) by off-loading implementations of data structures on to an available (but insecure, untrusted) fast coprocessor. However, d... | Introduction
Smart cards, set-top boxes, consumer electronics
and other forms of trusted hardware [2, 3, 16] have
been available (or are being proposed [1]) for applications
such as electronic commerce. We shall refer to
these devices as T . These devices are typically composed
of a circuit card encased in epoxy or a s... | software protection;correctness of memories;oblivious ram;data structures;security |
513337 | On Computing Structural Changes in Evolving Surfaces and their Appearance. | As a surface undergoes a one-parameter family of deformations, its shape and its appearance change smoothly except at certain critical parameter values where abrupt structural changes occur. This paper considers the case of surfaces defined as the zero set of smooth density functions undergoing a Gaussian diffusion pro... | Introduction
This article is concerned with the interplay of scale and shape in computer vision. Con-
cretely, imagine a smooth density function defined over some volume. The points where
the density exceeds a given threshold form a solid whose boundary is a level set of this
function. Smoothing the density changes its... | algebraic surfaces;differential geometry;aspect graphs;shape representation;scale space |
513398 | Affine Type A Crystal Structure on Tensor Products of Rectangles, Demazure Characters, and Nilpotent Varieties. | Answering a question of Kuniba, Misra, Okado, Takagi, and Uchiyama, it is shown that certain higher level Demazure characters of affine type A, coincide with the graded characters of coordinate rings of closures of conjugacy classes of nilpotent matrices. | Introduction
In [9, Theorem 5.2] it was shown that the characters of certain level one Demazure
modules of type A (1)
decomposed as linear combinations of irreducible
characters of type An\Gamma1 , have coefficients given by Kostka-Foulkes polynomials in
the variable is the null root. The key steps in the proof are tha... | tableau;littlewood-richardson coefficient;crystal graph;kostka polynomial |
513418 | Guaranteed. | We describe a distributed memory parallel Delaunay refinement algorithm for polyhedral domains which can generate meshes containing tetrahedra with circumradius to shortest edge ratio less than 2, as long as the angle separating any two incident segments and/or facets is between 90 and 270 degrees. Input to our impleme... | INTRODUCTION
A recent trend in many control systems is to connect distributed elements of a control system via a shared
broadcast bus instead of using point-to-point links [1]. However, there are fundamental differences between a
shared bus and point-to-point links. Firstly, because the bus is shared between a number o... | guaranteed-quality mesh generation;delaunay triangulation;parallel mesh generation |
513453 | Towards Intelligent Semantic Caching for Web Sources. | An intelligent semantic caching scheme suitable for web sources is presented. Since web sources typically have weaker querying capabilities than conventional databases, existing semantic caching schemes cannot be directly applied. Our proposal takes care of the difference between the query capabilities of an end user... | Introduction
Web databases allow users to pose queries to distributed and heterogeneous
web sources. Such systems usually consist of three components
(Adali et al., 1996; Garc'ia-Molina et al., 1995): 1) mediators to
provide a distributed, heterogeneous data integration, 2) wrappers to
provide a local translation and e... | web database;semantic caching;query matching;semantic locality |
513542 | Robust Learning with Missing Data. | This paper introduces a new method, called the robust Bayesian estimator (RBE), to learn conditional probability distributions from incomplete data sets. The intuition behind the RBE is that, when no information about the pattern of missing data is available, an incomplete database constrains the set of all possible es... | Introduction
Probabilistic methods play a central role in the development of Artificial
Intelligence (AI) applications because they can deal with for the degrees
of uncertainty so often embedded into real-world problems within a sound
mathematical framework. Unfortunately, the number of constraints needed
to define a p... | bayesian learning;bayesian networks;bayesian classifiers;missing data;probability intervals |
513803 | Routing performance in the presence of unidirectional links in multihop wireless networks. | We examine two aspects concerning the influence of unidirectional links on routing performance in multihop wireless networks. In the first part of the paper we evaluate the benefit from utilizing unidirectional links for routing as opposed to using only bidirectional links. Our evaluations are based on three transmit p... | INTRODUCTION
A unidirectional link arises between a pair of nodes in a network
when only one of the two nodes can directly communicate with
the other node. In multihop wireless networks (also known as ad
hoc networks), unidirectional links originate because of several rea-
sons. These include difference in radio transc... | routing;asymmetric links;multihop wireless networks;ad hoc networks;on-demand routing;unidirectional links;multipath routing |
513809 | Priority scheduling in wireless ad hoc networks. | Ad hoc networks formed without the aid of any established infrastructure are typically multi-hop networks. Location dependent contention and "hidden terminal" problem make priority scheduling in multi-hop networks significantly different from that in wireless LANs. Most of the prior work related to priority scheduling ... | INTRODUCTION
With advances in wireless communications and the growth
of real-time applications, wireless networks that support quality
of service (QoS) have recently drawn a lot of attention.
In order to provide di#erentiated service to real-time and
non-real-time packets, the medium access control protocol
must provid... | ad hoc network;busy tone;medium access control;priority scheduling |
513818 | Minimum energy paths for reliable communication in multi-hop wireless networks. | Current algorithms for minimum-energy routing in wireless networks typically select minimum-cost multi-hop paths. In scenarios where the transmission power is fixed, each link has the same cost and the minimum-hop path is selected. In situations where the transmission power can be varied with the distance of the link, ... | INTRODUCTION
Multi-hop wireless networks typically possesstwo important characteristics
1. The battery power available on the constituent lightweight mobile
nodes(such as sensornodes or smart-phones) is relatively
limited.
2. Communication costs (in terms of transmission energy required)
are often much higher than com... | routing;energy efficiency;ad-hoc networks |
513826 | Weak duplicate address detection in mobile ad hoc networks. | Auto-configuration is a desirable goal in implementing mobile ad hoc networks. Specifically, automated dynamic assignment (without manual intervention) of IP addresses is desirable. In traditional networks, such dynamic address assignment is often performed using the Dynamic Host Configuration Protocol (DHCP). Implemen... | INTRODUCTION
Auto-configuration is a desirable goal in implementing
mobile ad hoc networks [16]. Specifically, automated dynamic
assignment of IP addresses is desirable. In traditional
networks, such dynamic address assignment is often
performed using Dynamic Host Configuration Protocol
(DHCP) [5]. Implementing DHCP, h... | mobile ad hoc networks;auto-configuration;duplicate address detection |
513853 | Efficient register and memory assignment for non-orthogonal architectures via graph coloring and MST algorithms. | Finding an optimal assignment of program variables into registers and memory is prohibitively difficult in code generation for application specific instruction-set processors (ASIPs). This is mainly because, in order to meet stringent speed and power requirements for embedded applications, ASIPs commonly employ non-ort... | INTRODUCTION
As embedded system designers strive to meet cost and performance
goals demanded by the applications, the complexity
of processors is ever increasingly optimized for certain application
domains in embedded systems. Such optimizations
need a process of design space exploration [8] to find hardware
configurat... | compiler;memory assignment;non-orthogonal architecture;dual memory;maximum spanning tree;graph coloring |
513858 | Compiler-directed cache polymorphism. | Classical compiler optimizations assume a fixed cache architecture and modify the program to take best advantage of it. In some cases, this may not be the best strategy because each loop nest might work best with a different cache configuration and transforming a nest for a given fixed cache configuration may not be po... | INTRODUCTION
Most of today's microprocessor systems include several special
architectural features (e.g., large on-chip caches) that use
a significant fraction of on-chip transistors. These complex
and energy-hungry features are meant to be applicable across
different application domains. However, they are effectively
... | compilers;energy consumption;embedded software;cache polymorphism;data reuse;cache locality |
514027 | Fast three-level logic minimization based on autosymmetry. | Sum of Pseudoproducts (SPP) is a three level logic synthesis technique developed in recent years. In this framework we exploit the "regularity" of Boolean functions to decrease minimization time. Our main results are: 1) the regularity of a Boolean function of n variables is expressed by its autosymmetry degree k (wit... | Introduction
The standard synthesis of Boolean functions is performed with Sum of Products (SP) minimization
procedures, leading to two level circuits. More-than-two level minimization is much harder, but
the size of the circuits can signicantly decrease. In many cases three-level logic is a good trade-o
among circuit ... | three-level logic;synthesis;autosymmetry |
514118 | Deriving a simulation input generator and a coverage metric from a formal specification. | This paper presents novel uses of functional interface specifications for verifying RTL designs. We demonstrate how a simulation environment, a correctness checker, and a functional coverage metric are all created automatically from a single specification. Additionally, the process exploits the structure of a specifica... | INTRODUCTION
1.1 Motivation
Before a verification engineer can start simulating RTL designs,
he must write three verification aids: input testbenches to stimulate
the design, properties to verify the behavior, and a functional
coverage metric to quantify simulation progress. It would be much
easier if the three can be ... | coverage;BDD minimization;testbench;input generation |
514214 | Markov model prediction of I/O requests for scientific applications. | Given the increasing performance disparity between processors and storage devices, exploiting knowledge of spatial and temporal I/O requests is critical to achieving high performance, particularly on parallel systems. Although perfect foreknowledge of I/O requests is rarely possible, even estimates of request patterns ... | INTRODUCTION
The disparity between processor and disk performance
continues to increase, driven by market economics that reward
high-performance processors and high-capacity storage
devices. As parallel systems (e.g., clusters) are increasingly
constructed using large numbers of commodity components,
This work was supp... | storage;markov model;parallel computing |
514234 | Near-optimal adaptive control of a large grid application. | This paper develops a performance model that is used to control the adaptive execution the ATR code for solving large stochastic optimization problems on computational grids. A detailed analysis of the execution characteristics of ATR is used to construct the performance model that is then used to specify (a) near-opti... | INTRODUCTION
This paper develops a model for near-optimal adaptive control of
the state-of-the-art stochastic optimization code ATR [18] on Grid
platforms such as Condor [19], Globus [10], or Legion [13], in
which the number and capabilities of the distributed hosts that
execute ATR varies during the course of the comp... | parallel algorithms;grid computing;parallel application performance;adaptive computations;stochastic optimization |
52795 | Absolute Bounds on Set Intersection and Union Sizes from Distribution Information. | A catalog of quick closed-form bounds on set intersection and union sizes is presented; they can be expressed as rules, and managed by a rule-based system architecture. These methods use a variety of statistics precomputed on the data, and exploit homomorphisms (onto mappings) of the data items onto distributions that ... | r
e
methods for data in a database, especially when joins are involved. Such estimation is necessary fo
stimates of paging or blocks required. But often absolute bounds on such sizes can serve the purpose
of estimates, for several reasons:
1. Absolute bounds are more often possible to compute than estimates. Estimates ... | distribution information;closed-form bounds;database theory;statistical analysis;set theory;union sizes;file organisation;set intersection;boolean algebra;database access;rule-based system architecture |
543016 | Contour and Texture Analysis for Image Segmentation. | This paper provides an algorithm for partitioning grayscale images into disjoint regions of coherent brightness and texture. Natural images contain both textured and untextured regions, so the cues of contour and texture differences are exploited simultaneously. Contours are treated in the intervening contour framework... | Introduction
Submitted to the International Journal of Computer Vision, Dec 1999
A shorter version appeared in the International Conference in Computer Vision, Corfu, Greece, Sep 1999
To humans, an image is not just a random collection of pixels; it
is a meaningful arrangement of regions and objects. Figure 1 shows a
v... | segmentation;normalized cut;grouping;cue integration;texton;texture |
543174 | Norm-Based Approximation in Bicriteria Programming. | An algorithm to approximate the nondominated set of continuous and discrete bicriteria programs is proposed. The algorithm employs block norms to find an approximation and evaluate its quality. By automatically adapting to the problem's structure and scaling, the approximation is constructed objectively without interac... | Introduction
In view of increased computational power and enhanced graphic capabilities
of computers, approximation of the solution set for bicriteria programming
has been a research topic of special interest. Since bicriteria programs feature
only two criteria, their solution set can be visualized graphically which
si... | nondominated points;block norms;approximation;bicriteria programs |
544758 | Risk and expectations in a-priori time allocation in multi-agent contracting. | In related research we have proposed a market architecture for multi-agent contracting and we have implemented prototypes of both the market architecture and the agents in a system called MAGNET. A customer agent in MAGNET solicits bids for the execution of multi-step plans, in which tasks have precedence and time cons... | INTRODUCTION
The MAGNET (Multi-AGent NEgotiation Testbed) [4]
system is designed to support multiple agents in negotiating
Permission to make digital or hard copies of all or part of this work for
personal or classroom use is granted without fee provided that copies are
not made or distributed for profit or commercial ... | multi-agent contracting;automated auctions;risk estimation;expected utility |
544775 | Multi-issue negotiation under time constraints. | This paper presents a new model for multi-issue negotiation under time constraints in an incomplete information setting. In this model the order in which issues are bargained over and agreements are reached is determined endogenously as part of the bargaining equilibrium. We show that the sequential implementation of t... | INTRODUCTION
Agent mediated negotiation has received considerable attention in
the field of electronic commerce [14, 9, 7]. In many of the applications
that are conceived in this domain it is important that the
agents should not only bargain over the price of a product, but also
take into account aspects like the deliv... | game theory;agendas;negotiation |
544819 | Interacting with virtual characters in interactive storytelling. | In recent years, several paradigms have emerged for interactive storytelling. In character-based storytelling, plot generation is based on the behaviour of autonomous characters. In this paper, we describe user interaction in a fully-implemented prototype of an interactive storytelling system. We describe the planning ... | Figure
1).
Figure
1. A story instantiation generated by the system: Ross
asks Phoebe Rachel's preferences, but Phoebe lies to him.
The graphic environment for our system is based on the Unreal
computer game engine. Other researchers in the field of
interactive storytelling have previously described the use of the
sa... | interactive storytelling;computer games;planning;synthetic characters;speech understanding |
544835 | An analysis of formal inter-agent dialogues. | This paper studies argumentation-based dialogues between agents. It defines a set of locutions by which agents can trade arguments, a set of agent attitudes which relate what arguments an agent can build and what locutions it can make, and a set of protocols by which dialogues can be carried out. The paper then conside... | INTRODUCTION
When building multi-agent systems, we take for granted
the fact that the agents which make up the system will need
to communicate. They need to communicate in order to
resolve dierences of opinion and con
icts of interest, work
together to resolve dilemmas or nd proofs, or simply to
inform each other of pe... | agent communication;argumentation;dialogue games |
544836 | Desiderata for agent argumentation protocols. | Designers of agent communications protocols are increasingly using formal dialogue games, adopted from argumentation theory, as the basis for structured agent interactions. We propose a set of desiderata for such protocols, drawing on recent research in agent interaction, on recent criteria for assessment of automated ... | INTRODUCTION
Formal dialogue games are games in which two or more participants
"move" by uttering locutions, according to certain pre-defined
rules. They have been studied by philosophers since the time of
Aristotle, most recently for the contextual modeling of fallacious
reasoning [14, 23] and as a proof-theoretic sem... | interaction protocols;FIPA;argumentation;dialogue games;agent communication languages |
544923 | A problem solving model for collaborative agents. | This paper describes a model of problem solving for use in collaborative agents. It is intended as a practical model for use in implemented systems, rather than a study of the theoretical underpinnings of collaborative action. The model is based on our experience in building a series of interactive systems in different... | INTRODUCTION
One of the most general models for interaction between
humans and autonomous agents is based on natural human-human
dialogue. For humans, this is an interface that requires
no learning, and provides maximum
exibility and
generality. To build such an interface on the autonomous
agent side, however, is a for... | conversational agents;interface agents;intention recognition;coordinating multiple agents and activities |
545103 | A study on the termination of negotiation dialogues. | Dialogue represents a powerful means to solve problems using agents that have an explicit knowledge representation, and exhibit a goal-oriented behaviour. In recent years, computational logic gave a relevant contribution to the development of Multi-Agent Systems, showing that a logic-based formalism can be effectively ... | Introduction
Dialogue is one of the most
exible interaction patterns in Multi-Agent Systems,
being something between completely xed protocols and totally free conversations
[3]. Intuitively, a dialogue is not the (purely reactive) question-answer sequence
of a client server architecture framed in a rigid protocol, but ... | abduction;multi-agent systems;computational logic;dialogue;negotiation;termination |
545117 | Channeled multicast for group communications. | Multi-agent systems can benefit from the possibility of broadcasting messages to a wide audience. The audience may include overhearing agents which, unknown to senders, observe conversations and, among other things, pro-actively send suggestions. Current mainstream agent communication languages however lack adequate su... | INTRODUCTION
While developing some collaborative, distributed applica-
tions, we realized that many multi-agent systems would ben-
et from the possibility of broadcasting messages to a wide
audience, which may include overhearing agents unknown
to the senders. We even based an abstract architecture [5]
on the ability o... | auction protocols;group communications;overhearing;broadcasting;agent communication languages;multicasting |
545223 | A large, fast instruction window for tolerating cache misses. | Instruction window size is an important design parameter for many modern processors. Large instruction windows offer the potential advantage of exposing large amounts of instruction level parallelism. Unfortunately naively scaling conventional window designs can significantly degrade clock cycle time, undermining the b... | Introduction
Many of today's microprocessors achieve high performance
by combining high clock rates with the ability to dynamically
process multiple instructions per cycle. Unfortu-
nately, these two important components of performance are
often at odds with one another. For example, small hardware
structures are usual... | latency tolerance;instruction window;memory latency;cache memory |
545235 | Using a user-level memory thread for correlation prefetching. | This paper introduces the idea of using a User-Level Memory Thread (ULMT) for correlation prefetching. In this approach, a user thread runs on a general-purpose processor in main memory, either in the memory controller chip or in a DRAM chip. The thread performs correlation prefetching in software, sending the prefetch... | Introduction
Data prefetching is a popular technique to tolerate long memory access
latencies. Most of the past work on data prefetching has focused
on processor-side prefetching [6, 7, 8, 12, 13, 14, 15, 19, 20, 23, 25,
26, 28, 29]. In this approach, the processor or an engine in its cache
hierarchy issues the prefetc... | intelligent memory;computer architecture;processing-in-memory;data prefetching;caches;memory hierarchies;correlation prefetching;threads |
545249 | Design tradeoffs for the Alpha EV8 conditional branch predictor. | This paper presents the Alpha EV8 conditional branch predictor The Alpha EV8 microprocessor project, canceled in June 2001 in a late phase of development, envisioned an aggressive 8-wide issue out-of-order superscalar microarchitecture featuring a very deep pipeline and simultaneous multithreading. Performance of such ... | Introduction
The Alpha EV8 microprocessor [2] features a 8-wide superscalar
deeply pipelined microarchitecture. With minimum
branch misprediction penalty of 14 cycles, the performance
of this microprocessor is very dependent on the
branch prediction accuracy. The architecture and technology
of the Alpha EV8 are very ag... | EV8 processor;branch prediction |
545273 | A practical model for hair mutual interactions. | Hair exhibits strong anisotropic dynamic properties which demand distinct dynamic models for single strands and hair-hair interactions. While a single strand can be modeled as a multibody open chain expressed in generalized coordinates, modeling hair-hair interactions is a more difficult problem. A dynamic model for th... | In this paper, we focus on the dynamics of long hair, and hair mutual
interactions in particular. Hair has highly anisotropic dynamic
Email: {jtchang, jingjin, yyz}@uiuc.edu
Website: www-faculty.cs.uiuc.edu/yyz/research/hair/
properties, i.e. hair strands are extremely hard to stretch but free to
move laterally and int... | static links;open chain;hair rendering;collision detection;hair-hair interaction;hair animation |
545340 | On a New Homotopy Continuation Trajectory for Nonlinear Complementarity Problems. | Most known continuation methods for P 0 complementarity problems require some restrictive assumptions, such as the strictly feasible condition and the properness condition, to guarantee the existence and the boundedness of certain homotopy continuation trajectory. To relax such restrictions, we propose a new homotopy f... | Introduction
. We denote by R n the n-dimensional Euclidean space, R n
the nonnegative
orthant, and R n
++ the positive orthant. For simplicity, we also denote x 2 R n
(R n
by x - In this paper, all vectors are column vectors, and superscript T denotes
the transpose. e is the vector of all ones in R n : For any x 2 R n... | homotopy continuation trajectories;p-functions;strictly feasible condition;continuation methods;complementarity problems;P0-functions |
545541 | View updates in a semantic data modelling paradigm. | The Sketch Data Model (SkDM) is a new semantic modelling paradigm based on category theory (specifically on categorical universal algebra), which has been used successfully in several consultancies with major Australian companies. This paper describes the sketch data model and investigates the view update problem (VUP)... | Introduction
This is a paper about the view update problem in the
framework of a new semantic data model, the sketch data
model.
View updating has long been recognised as important
and difficult (see for example [11, Chapter 8]). With the
growth of the need for database interoperability and graceful
evolution, the impo... | category theory;view update;data model;semantic data modelling |
563832 | An approach to phrase selection for offline data compression. | Recently several offline data compression schemes have been published that expend large amounts of computing resources when encoding a file, but decode the file quickly. These compressors work by identifying phrases in the input data, and storing the data as a series of pointer to these phrases. This paper explores the... | Introduction
If data is to be stored on CD, DVD or in a static
database it will be compressed once, but often decompressed
many times. Given this scenario, a compression
scheme can aord to spend several hours of
computing time, make multiple passes over the input,
and consume many megabytes of RAM during the
compressio... | strings;textual substitution;repeating substrings;offline data compression |
563924 | UML and XML schema. | XML is rapidly becoming the standard method for sending information across the Internet. XML Schema, since its elevation to W3C Recommendation on the 2nd May 2001, is fast becoming the preferred means of describing structured XML data. However, until recently, there has been no effective means of graphically designing ... | Figure
1: Three level design approach
As mentioned, the Universe of Discourse (UoD) being
modeled in XML schema is a university student-rating
system (as shown in the following two output reports).
Subject Title Year NrEnrolled Lecturer
CS100 Intro to Computer 1982 200 P.L.
Science Cook
Engineering
CS100 Intro to Comp... | UML;XML;XML Schema;DTD |
563925 | Compacting discriminator information for spatial trees. | Cache-conscious behaviour of data structures becomes more important as memory sizes increase and whole databases fit into main memory. For spatial data, R-trees, originally designed for disk-based data, can be adopted for in-memory applications. In this paper, we will investigate how the small amount of space in an in-... | Introduction
Latest surveys have shown that the availability of
cheap memory will lead to computer systems with
main memory sizes in the order of terrabytes over
the next 10 years [Bernstein et al., 1998]. Many
databases will then t entirely in main memory. For
database technology, this means that the traditional
bottl... | in-memory databases;spatial databases;index structures |
564104 | Distributed component architecture for scientific applications. | The ideal goal of not having the user dealing with concurrency aspects has proven hard to achieve in the context of system (compiler, run-time) supported automatic parallelization for general purpose languages and applications. More focused approaches, of automatic parallelization for numerical applications with a regu... | Introduction
Most of the scientic computing applications are concerned
with the solution of the Partial Dierential
Equations (PDEs) which describe some physical phe-
nomena. Typical application areas are computa-
tional
uid dynamics, computational biology, and so
forth. The solution of PDEs, either by Finite Element
Me... | generic programming;concurrency;scientific applications;distributed components |
564387 | Two-stage language models for information retrieval. | The optimal settings of retrieval parameters often depend on both the document collection and the query, and are usually found through empirical tuning. In this paper, we propose a family of two-stage language models for information retrieval that explicitly captures the different influences of the query and document c... | INTRODUCTION
It is well-known that the optimal settings of retrieval parameters
generally depend on both the document collection and the query.
Permission to make digital or hard copies of all or part of this work for
personal or classroom use is granted without fee provided that copies are
not made or distributed for ... | interpolation;risk minimization;two-stage smoothing;parameter estimation;leave-one-out;mixture model;two-stage language models;dirichlet prior |
564395 | Bayesian online classifiers for text classification and filtering. | This paper explores the use of Bayesian online classifiers to classify text documents. Empirical results indicate that these classifiers are comparable with the best text classification systems. Furthermore, the online approach offers the advantage of continuous learning in the batch-adaptive text filtering task. | INTRODUCTION
Faced with massive information everyday, we need automated
means for classifying text documents. Since hand-crafting
text classifiers is a tedious process, machine learning
methods can assist in solving this problem[15, 7, 27].
Yang & Liu[27] provides a comprehensive comparison of
supervised machine learni... | text classification;text filtering;online;bayesian;machine learning |
564404 | A new family of online algorithms for category ranking. | We describe a new family of topic-ranking algorithms for multi-labeled documents. The motivation for the algorithms stems from recent advances in online learning algorithms. The algorithms we present are simple to implement and are time and memory efficient. We evaluate the algorithms on the Reuters-21578 corpus and th... | INTRODUCTION
The focus of this paper is the problem of topic ranking for
text documents. We use the Reuters corpus (release 2000)
as our running example. In this corpus there are about a
hundred dierent topics. Each document in the corpus is
tagged with a set of topics that are relevant to its content.
For instance, a ... | online learning;category ranking;perceptrons |
564406 | Comparing cross-language query expansion techniques by degrading translation resources. | The quality of translation resources is arguably the most important factor affecting the performance of a cross-language information retrieval system. While many investigations have explored the use of query expansion techniques to combat errors induced by translation, no study has yet examined the effectiveness of the... | INTRODUCTION
Cross-Language Information Retrieval (CLIR) systems seek to
identify pertinent information in a collection of documents
containing material in languages other than the one in which the
user articulated her query. Intrinsic to the problem is a need to
transform the query, document, or both, into a common
te... | query expansion;query translation;cross-language information retrieval;translation resources |
564412 | Document clustering with committees. | Document clustering is useful in many information retrieval tasks: document browsing, organization and viewing of retrieval results, generation of Yahoo-like hierarchies of documents, etc. The general goal of clustering is to group data elements such that the intra-group similarities are high and the inter-group simila... | INTRODUCTION
Document clustering was initially proposed for improving the
precision and recall of information retrieval systems [18]. Because
clustering is often too slow for large corpora and has indifferent
performance [8], document clustering has been used more
recently in document browsing [3], to improve the organ... | document representation;document clustering;evaluation methodology;machine learning |
564435 | Robust temporal and spectral modeling for query By melody. | Query by melody is the problem of retrieving musical performances from melodies. Retrieval of real performances is complicated due to the large number of variations in performing a melody and the presence of colored accompaniment noise. We describe a simple yet effective probabilistic model for this task. We describe a... | INTRODUCTION
A natural way for searching a musical audio database for
a song is to look for a short audio segment containing a
melody from the song. Most of the existing systems are
based on textual information, such as the title of the song
and the name of the composer. However, people often do
not remember the name o... | spectral modeling;query by melody;graphical models;music information retrieval |
564880 | Distributed streams algorithms for sliding windows. | This paper presents algorithms for estimating aggregate functions over a "sliding window" of the N most recent data items in one or more streams. Our results include:<ol>For a single stream, we present the first &egr;-approximation scheme for the number of 1's in a sliding window that is optimal in both worst case time... | INTRODUCTION
There has been a
urry of recent work on designing effective
algorithms for estimating aggregates and statistics
over data streams [1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 14, 15, 16,
17, 18, 19, 25], due to their importance in applications such
as network monitoring, data warehousing, telecommunica-
tions, and sen... | waves;sliding windows;distributed;data streams |
564915 | Algorithms for fault-tolerant routing in circuit switched networks. | In this paper we consider the k edge-disjoint paths problem (k-EDP), a generalization of the well-known edge-disjoint paths problem. Given a graph G=(V,E) and a set of terminal pairs (or requests) T, the problem is to find a maximum subset of the pairs in T for which it is possible to select paths such that each pair i... | Introduction
This paper was motivated by a talk given by Rakesh Sinha from Ciena Inc. at
the DIMACS Workshop on Resource Management and Scheduling in Next Generation
Networks, March 26-27, 2001. The speaker pointed out in his talk that
standard problems such as the edge-disjoint paths problem and the unsplittable
ow pr... | multicommodity flow;fault-tolerant routing;greedy algorithms;flow number;edge-disjoint paths |
564916 | Parallel dynamic programming for solving the string editing problem on a CGM/BSP. | In this paper we present a coarse-grained parallel algorithm for solving the string edit distance problem for a string A and all substrings of a string C. Our method is based on a novel CGM/BSP parallel dynamic programming technique for computing all highest scoring paths in a weighted grid graph. The algorithm require... | INTRODUCTION
Molecular Biology is an important field of application for
parallel computing. Sequence comparison is among the fundamental
tools in Computational Molecular Biology and is
used to solve more complex problems [14], including the
computation of similarities between biosequences [11, 13,
15]. Beside such Mole... | parallel algorithms;BSP;CGM;string editing;dynamic programming |
566175 | Model checking Java programs using structural heuristics. | We describe work in troducing heuristic search into the Java PathFinder model checker, which targets Java bytecode. Rather than focusing on heuristics aimed at a particular kind of error (such as deadlocks) we describe heuristics based on a modification of traditional branch coverage metrics and other structure measure... | INTRODUCTION
There has been recent interest in model checking software
written in real programming languages [3, 10, 15, 24, 25, 33]
and in using heuristics to direct exploration in explicit-state
model checkers [12, 35]. Because heuristic-guided search is
clearly directed at nding errors rather than verifying the
comp... | coverage metrics;heuristics;testing;model checking |
566199 | Specification, verification, and synthesis of concurrency control components. | Run-time errors in concurrent programs are generally due to the wrong usage of synchronization primitives such as monitors. Conventional validation techniques such as testing become ineffective for concurrent programs since the state space increases exponentially with the number of concurrent processes. In this paper, ... | INTRODUCTION
Writing a concurrent program is an error prone task. A
concurrent programmer has to keep track of not only the
possible values of the variables of the program, but also the
states of its concurrent processes. Failing to use concurrency
constructs such as semaphores or monitors correctly
results in run-time... | concurrent programming;specification languages;infinite-state model checking;monitors |
566236 | Deterministic parallel backtrack search. | The backtrack search problem involves visiting all the nodes of an arbitrary binary tree given a pointer to its root subject to the constraint that the children of a node are revealed only after their parent is visited. We present a fast, deterministic backtrack search algorithm for a p-processor COMMON CRCW-PRAM, whic... | Introduction
Several algorithmic techniques, such as those employed for solving many optimization
problems, are based on the systematic exploration of a tree, whose
internal nodes correspond to partial solutions (growing progressively more rened
with increasing depth) and whose leaves correspond to feasible solutions.
... | load balancing;parallel algorithms;PRAM model;backtrack search |
566244 | Decision lists and related Boolean functions. | We consider Boolean functions represented by decision lists, and study their relationships to other classes of Boolean functions. It turns out that the elementary class of 1-decision lists has interesting relationships to independently defined classes such as disguised Horn functions, read-once functions, nested differ... | Introduction
Decision lists have been proposed in [31] as a specification of Boolean functions which amounts to a simple
strategy for evaluating a Boolean function on a given assignment. This approach has been become popular
in learning theory, since bounded decision lists naturally generalize other important classes o... | polynomial delay enumeration;extension problem;boolean functions;decision lists;teaching sequence |
566245 | Asymptotic behavior in a heap model with two pieces. | In a heap model, solid blocks, or pieces, pile up according to the Tetris game mechanism. An optimal schedule is an infinite sequence of pieces minimizing the asymptotic growth rate of the heap. In a heap model with two pieces, we prove that there always exists an optimal schedule which is balanced, either periodic or ... | Introduction
Heap models have recently been studied as a pertinent model of discrete event
systems, see Gaubert & Mairesse [19,20] and Brilman & Vincent [12,13]. They
provide a good compromise between modeling power and tractability. As far
as modeling is concerned, heap models are naturally associated with trace
monoi... | timed Petri net;optimal scheduling;heap of pieces;+ semiring;sturmian word;tetris game;automaton with multiplicities |
566247 | Computational complexity of some problems involving congruences on algebras. | We prove that several problems concerning congruences on algebras are complete for nondeterministic log-space. These problems are: determining the congruence on a given algebra generated by a set of pairs, and determining whether a given algebra is simple or subdirectly irreducible. We also consider the problem of dete... | A and a lies in
the subuniverse of A generated by
It is easy to nd a reduction of Gen-Con to Gen-SubAlg, see for example,
[3, Theorem 5.5]. Thus Gen-Con can be no harder than Gen-SubAlg.
However, in [14] Jones and Laaser proved that Gen-SubAlg is complete
for P (the class of problems solvable in polynomial time). It i... | simple algebra;nondeterministic log-space;congruence;graph accessibility |
566248 | Decision tree approximations of Boolean functions. | Decision trees are popular representations of Boolean functions. We show that, given an alternative representation of a Boolean function f, say as a read-once branching program, one can find a decision tree T which approximates f to any desired amount of accuracy. Moreover, the size of the decision tree is at most that... | Introduction
Decision trees are popular representations of Boolean func-
tions. They form the basic inference engine in well-known
machine learning programs such as C4.5 [Q86, Q96]. Boolean
decision trees have also been used in the problem of performing
reliable computations in the presence of faulty components
[KK94] ... | representations of Boolean functions;learning theory;algorithms;decision trees |
566251 | On two-sided infinite fixed points of morphisms. | Let &Sgr; be a finite alphabet, and let h:&Sgr;*&Sgr; be a morphism. Finite and infinite fixed points of morphismsi.e., those words w such that h(w)=wplay an important role in formal language theory. Head characterized the finite fixed points of h, and later, Head and Lando characterized the one-sided infinite fixed po... | called the Thue-Morse infinite word, is the unique one-sided infinite fixed point of which
starts with 0. In fact, nearly every explicit construction of an infinite word avoiding certain
patterns involves the fixed point of a morphism; for example, see [8, 15, 24, 20]. One-sided
infinite fixed points of uniform morphi... | fixed point;combinatorics on words;morphism;infinite words |
566252 | Weak bisimilarity between finite-state systems and BPA or normed BPP is decidable in polynomial time. | We prove that weak bisimilarity is decidable in polynomial time between finite-state systems and several classes of infinite-state systems: context-free processes and normed basic parallel processes (normed BPP). To the best of our knowledge, these are the first polynomial algorithms for weak bisimilarity problems invo... | Introduction
Recently, a lot of attention has been devoted to the study of decidability
and complexity of verification problems for infinite-state systems [33,12,5].
We consider the problem of weak bisimilarity between certain infinite-state
processes and finite-state ones. The motivation is that the intended behavior
... | concurrency;bisimulation;infinite-state systems;process algebras;verification |
566387 | Polynomial-time computation via local inference relations. | We consider the concept of a local set of inference rules. A local rule set can be automatically transformed into a rule set for which bottom-up evaluation terminates in polynomial time. The local-rule-set transformation gives polynomial-time evaluation strategies for a large variety of rule sets that cannot be given t... | INTRODUCTION
Under what conditions does a given set of inference rules define a computationally tractable inference
relation? This is a syntactic question about syntactic inference rules. There are a variety of
motivations for identifying tractable inference relations. First, tractable inference relations sometimes
pro... | automated reasoning;descriptive complexity theory;decision procedures |
566390 | Boolean satisfiability with transitivity constraints. | We consider a variant of the Boolean satisfiability problem where a subset ϵ of the propositional variables appearing in formula Fsat encode a symmetric, transitive, binary relation over N elements. Each of these relational variables, ei,j, for 1 i < j N, expresses whether or not the relation holds between elem... | Introduction
Consider the following variant of the Boolean satisfiability problem. We are given a Boolean
formula F sat over a set of variables V . A subset symbolically encodes a binary relation
over N elements that is reflexive, symmetric, and transitive. Each of these relational variables,
whether or not the relatio... | boolean satisfiability;formal verification;decision procedures |
566454 | Tradeoffs in power-efficient issue queue design. | A major consumer of microprocessor power is the issue queue. Several microprocessors, including the Alpha 21264 and POWER4TM, use a compacting latch-based issue queue design which has the advantage of simplicity of design and verification. The disadvantage of this structure, however, is its high power dissipation.In th... | INTRODUCTION
There are many complex tradeoffs that must be made to achieve
the goal of a power-efficient, yet high performance design. The
first is the amount of performance that must be traded off for lower
power. A second consideration that has received less attention is
the amount of redesign and verification effort... | banking;issue queue;non-compacting;low-power;microarchitecture;adaptation;compacting |
566530 | Optimal deterministic protocols for mobile robots on a grid. | This paper studies a system of m robots operating in a set of n work locations connected by aisles in a nxn grid, where mn.Form time to the robots need to move along the aisles, in order to visit disjoint sets of locations. The movement of the robots must comply with the following constraints: (1) no two robots can col... | Introduction
A Multi Robot Grid system (shortly, MRG) consists of m robots that operate in a set of
locations connected by aisles in a
n \Theta
grid [ST95]. At any time, the
robots are located at distinct grid nodes, and from time to time each robot is given a set of
work locations (targets) to be visited. The target s... | social laws;multirobot grid system;computational agents;routing protocol |
566580 | Creating models of truss structures with optimization. | We present a method for designing truss structures, a common and complex category of buildings, using non-linear optimization. Truss structures are ubiquitous in the industrialized world, appearing as bridges, towers, roof supports and building exoskeletons, yet are complex enough that modeling them by hand is time con... | Introduction
A recurring challenge in the field of computer graphics is the creation
of realistic models of complex man-made structures. The
standard solution to this problem is to build these models by hand,
but this approach is time consuming and, where reference images
are not available, can be difficult to reconcil... | constrained optimization;physically based modeling;truss structures;nonlinear optimization |
566638 | The SAGE graphics architecture. | The Scalable, Advanced Graphics Environment (SAGE) is a new high-end, multi-chip rendering architecture. Each single SAGE board can render in excess of 80 million fully lit, textured, anti-aliased triangles per second. SAGE brings high quality antialiasing filters to video rate hardware for the first time. To achieve t... | Overview
SAGE's block diagram is seen in figure 1. In this diagram we have
expanded out the external buses, internal FIFOs, and internal multiplexers
load-balancing switches so that the overall data flow and
required sorting may be more easily seen at the system level.
SAGE's inter-chip connections are typically unidi... | graphics hardware;rendering hardware;video;graphics systems;anti-aliasing;frame buffer algorithms;hardware systems |
566640 | Ray tracing on programmable graphics hardware. | Recently a breakthrough has occurred in graphics hardware: fixed function pipelines have been replaced with programmable vertex and fragment processors. In the near future, the graphics pipeline is likely to evolve into a general programmable stream processor capable of more than simply feed-forward triangle rendering.... | Introduction
Real-time ray tracing has been a goal of the computer-graphics
community for many years. Recently VLSI technology has reached
the point where the raw computational capability of a single chip
is sufficient for real-time ray tracing. Real-time ray tracing has
been demonstrated on small scenes on a single ge... | programmable graphics hardware;ray tracing |
566643 | Physically based modeling and animation of fire. | We present a physically based method for modeling and animating fire. Our method is suitable for both smooth (laminar) and turbulent flames, and it can be used to animate the burning of either solid or gas fuels. We use the incompressible Navier-Stokes equations to independently model both vaporized fuel and hot gaseou... | Figure
1: A turbulent gas flame model of a flamethrower.
events such as explosions where shock waves and other compressible
effects are important, see e.g. [Yngve et al. 2000] and [Neff and
Fiume 1999]. As low speed events, deflagrations can be modeled
using the equations for incompressible flow (as opposed to those f... | flames;stable fluids;incompressible flow;blackbody radiation;smoke;vorticity confinement;implicit surface;chemical reaction |
566644 | Structural modeling of flames for a production environment. | In this paper we describe a system for animating flames. Stochastic models of flickering and buoyant diffusion provide realistic local appearance while physics-based wind fields and Kolmogorov noise add controllable motion and scale. Procedural mechanisms are developed for animating all aspects of flame behavior includ... | Figure
1: A burning torch is waved through the air.
or can clearly be relaxed because the fluid is already acting
atypically.
Fire on the other hand, is a dramatic element that requires the
maximum level of control possible while maintaining a believable
appearance. We expect fire to look complex and unpredictable,
wh... | physically-based modeling;flames;animation systems;wind fields;convection;kolmogorov spectrum |
567177 | Tracking Mobile Units for Dependable Message Delivery. | As computing components get smaller and people become accustomed to having computational power at their disposal at any time, mobile computing is developing as an important research area. One of the fundamental problems in mobility is maintaining connectivity through message passing as the user moves through the networ... | Introduction
Mobile computing reflects a prevailing societal and technological trend towards ubiquitous access to computational
and communication resources. Wireless technology and the decreasing size of computer components allow users
to travel within the office building, from office to home, and around the country wi... | mobile computing;message delivery;diffusing computations |
567199 | On sparse evaluation representations. | The sparse evaluation graph has emerged over the past several years as an intermediate representation that captures the dataflow information in a program compactly and helps perform dataflow analysis efficiently. The contributions of this paper are three-fold: We present a linear time algorithm for constructing a varia... | Introduction
The technique of sparse evaluation has emerged, over the past several years, as an efficient way of performing
program analysis. Sparse evaluation is based on the simple observation that for any given analysis problem,
a number of the "statements" in a given program may be "irrelevant" with respect to the ... | equivalent flow graphs;sparse evaluation graphs;quick propagation graphs;graph transformations;dataflow analysis;static single assignment forms;partially equivalent flow graphs |
567200 | Logical optimality of groundness analysis. | In the context of the abstract interpretation theory, we study the relations among various abstract domains for groundness analysis of the logic programs. We reconstruct the well-known domain as a logical domain in a fully automatic way and we prove that it is the best abstract domain which can be set up from the prope... | Introduction
In the logic programming field, groundness is probably the most important instance
of static analysis. Many domains have been proposed in order to study
groundness of (pure) logic programs, from the very simple domain G by Jones
and Sndergaard [13], to more complex ones, like
The latter is the most widely ... | abstract domain;abstract interpretation;heyting completion;intuitionistic logic;static analysis;groundness;logic programming |
567275 | Estimation of state line statistics in sequential circuits. | In this article, we present a simulation-based technique for estimation of signal statistics (switching activity and signal probability) at the flip-flop output nodes (state signals) of a general sequential circuit. Apart from providing an estimate of the power consumed by the flip-flops, this information is needed for... | INTRODUCTION
The dramatic decrease in feature size and the corresponding increase in the
number of devices on a chip, combined with the growing demand for portable
communication and computing systems, have made power consumption one of
the major concerns in VLSI circuits and systems design [Brodersen et al. 1991].
Inde... | switching activity;transition density;signal statistics;sequential circuit;signal probability;power estimation;finite-state machine |
567809 | On computing givens rotations reliably and efficiently. | We consider the efficient and accurate computation of Givens rotations. When f and g are positive real numbers, this simply amounts to computing the values of apparently trivial computation merits closer consideration for the following three reasons. First, while the definitions of c, s and r seem obvious in the case o... | Introduction
Givens rotations are widely used in numerical linear algebra. Given f and g, a Givens rotation is a 2-by-2
unitary matrix R(c, s) such that
-s c
The fact that R(c, s) is unitary implies
-s c
c
# Computer Science Division University of California, Berkeley, CA 94720 (dbindel@cs.berkeley.edu). This material ... | givens rotation;BLAS;linear algebra |
568175 | Jones optimality, binding-time improvements, and the strength of program specializers. | Jones optimality tells us that a program specializer is strong enough to remove an entire level of self-interpretation. We show that Jones optimality, which was originally aimed at the Futamura projections, plays an important role in binding-time improvements. The main results show that, regardless of the binding-time ... | INTRODUCTION
Binding-time improvements are semantics-preserving
transformations that are applied to a source program prior
to program specialization. Instead of specializing the original
program, the modified program is specialized. The goal
is to produce residual programs that are better in some
sense than the ones pr... | futamura projections;metacomputation;interpretive approach;jones optimality;binding-time improvements;self-interpreters;specializer projections |
568176 | Search-based binding time analysis using type-directed pruning. | We introduce a new way of performing binding time analysis. Rather than analyzing the program using constraint solving or abstract interpretation, we use a method based on search. The search is guided by type information which significantly prunes the size of the search space, making the algorithm practical. Our claim ... | INTRODUCTION
Binding Time Analysis (BTA) can be thought of as the
automatic addition of staging annotations to a well-typed,
semantically meaningful term in some base language. The
Permission to make digital or hard copies of all or part of this work for
personal or classroom use is granted without fee provided that co... | type-directed search;binding time analysis;staging |
568177 | On obtaining Knuth, Morris, and Pratt''s string matcher by partial evaluation. | We present the first formal proof that partial evaluation of a quadratic string matcher can yield the precise behaviour of Knuth, Morris, and Pratt's linear string matcher.Obtaining a KMP-like string matcher is a canonical example of partial evaluation: starting from the naive, quadratic program checking whether a patt... | Introduction
Obtaining Knuth, Morris, and Pratt's linear string matcher out of a naive
quadratic string matcher is a traditional exercise in partial evaluation:
run match #pat , res
run PE #match , #pat ,
run match #pat, # , res
Given a static pattern, the partial evaluator should perform all backtracking
statically to... | trace semantics;data specialization;program specialization;Knuth-Morris-Pratt string matching |
568186 | Unifying object-oriented programming with typed functional programming. | The wide practice of object-oriented programming in current software construction is evident. Despite extensive studies on typing programming objects, it is still undeniably a challenging research task to design a type system for object-oriented programming that is both effective in capturing program errors and unobtru... | INTRODUCTION
The popularity of object-oriented programming in current
software practice is evident. While this popularity may result
in part from the tendency to chase after the latest "fads"
in programming languages, there is undeniably some real
substance in the growing use of object-oriented program-
ming. In partic... | dependent types;DML;object-oriented |
568265 | Primitives for authentication in process algebras. | We extend the &pgr;-calculus and the spi-calculus with two primitives that guarantee authentication. They enable us to abstract from various implementations/specifications of authentication, and to obtain idealized protocols which are "secure by construction". The main underlying idea, originally proposed in Focardi (P... | Introduction
Authentication is one of the main issues in security and it can have different purposes depending on the
specific application considered. For example, entity authentication is related to the verification of an entity's
claimed identity [18], while message authentication should make it possible for the rece... | secrecy;operational semantics;proved transition systems;distributed process algebras;authentication;security |
568275 | Listing all potential maximal cliques of a graph. | A potential maximal clique of a graph is a vertex set that induces a maximal clique in some minimal triangulation of that graph. It is known that if these objects can be listed in polynomial time for a class of graphs, the treewidth and the minimum fill-in are polynomially tractable for these graphs. We show here that ... | Introduction
The notion of treewidth was introduced at the beginning of the eighties by Robertson and
Seymour [25, 26] in the framework of their graph minor theory. A graph H is a minor of a
graph G if we can obtain H from G by using the following operations: discard a vertex, discard
an edge, merge the endpoints of an... | treewidth;potential maximal cliques;graph algorithms;minimal separators |
568282 | Binary (generalized) post correspondence problem. | We give a new proof for the decidability of the binary Post Correspondence Problem (PCP) originally proved in 1982 by Ehrenfeucht, Karhumki and Rozenberg. Our proof is complete and somewhat shorter than the original proof although we use the same basic. Copyright 2002 Elsevier Science B.V. All rights reserved. | Introduction
Let A and B be two nite alphabets and h; g be two morphisms
. The Post Correspondence Problem, PCP for short, is to determine if
there exists a nonempty word w 2 A such that It was proved
by Post [8] that this problem is undecidable in general. Such a word w that
called a solution of the instance (h; g) o... | marked morphisms;decidability;binary post correspondence problem;post correspondence problem;generalised post correspondence problem |
568285 | Decidability of EDT0L structural equivalence. | We show that a tree pushdown automaton can verify, for an arbitrary nondeterministically constructed structure tree t, that t does not correspond to any valid derivation of a given EDT0L grammar. In this way we reduce the structural equivalence problem for EDT0L grammars to deciding emptiness of the tree language recog... | Introduction
Context-free type grammars G 1 and G 2 are said to be structurally equivalent if, corresponding to
each syntax tree of G 1 producing a terminal word, the grammar G 2 has a syntax tree with the
same structure, and vice versa. The structure of a syntax tree t is the leaf-labeled tree obtained
from t by remov... | formal languages;tree pushdown automata;parallel grammars |
568337 | CSP, partial automata, and coalgebras. | The paper presents a first reconstruction of Hoare's theory of CSP in terms of partial automata and related coalgebras. We show that the concepts of processes in Hoare (Communicating Sequential Processes, Prentice-Hall, Englewood Cliffs, NJ, 1985) are strongly related to the concepts of states for special, namely, fina... | Introduction
For people usually working on model theory or semantics of formal specifications
it becomes often very hard to approach the area of process calculi and
process algebras.
There are processes without any physical basis. There is no difference
between concepts as machine, process, agent, state, and system. Th... | communicating sequential processes;partial automata;coalgebras;final automata |
568342 | Combining a monad and a comonad. | We give a systematic treatment of distributivity for a monad and a comonad as arises in giving category theoretic accounts of operational and denotational semantics, and in giving an intensional denotational semantics. We do this axiomatically, in terms of a monad and a comonad in a 2-category, giving accounts of the E... | Introduction
In recent years, there has been an ongoing attempt to incorporate operational
semantics into a category theoretic treatment of denotational semantics. The
denotational semantics is given by starting with a signature for a language
without variable binding, and considering the category -Alg of -algebras [4... | algebra;coalgebra;monad;comonad;2-category;distributive law;kleisli construction;bialgebra |
568396 | The theory of interactive generalized semi-Markov processes. | In this paper we introduce the calculus of interactive generalized semi-Markov processes (IGSMPs), a stochastic process algebra which can express probabilistic timed delays with general distributions and synchronizable actions with zero duration, and where choices may be probabilistic, non-deterministic and prioritized... | Introduction
Stochastically timed process algebras (see e.g. [20,12,1,6,10,16,28,5,11,17,22])
are formal specication languages which describe concurrent systems both
from the viewpoint of interaction and from the viewpoint of performance. They
extend the expressiveness of classical process algebras by introducing a not... | stochastic process algebras;probabilistic bisimulation;generalized semi-Markov processes;observational congruence |
568692 | Numerical Schemes for Variational Inequalities Arising in International Asset Pricing. | This paper introduces a valuation model of international pricing in the presence of political risk. Shipments between countries are charged with shipping costs and the country specific production processes are modelled as diffusion processes. The political risk is modelled as a continous time jump process that aff... | Introduction
We develop a continuous time model of international asset pricing in a two-country
framework with political risks. The structure of the model is similar to
Dumas (1992) except for the inclusion of political risk. Assets are homogeneous
except for location, and serve as production inputs as well as consumpt... | political risk;shipping costs;international asset pricing;gradient constraints;viscosity solutions;variational inequalities |
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